NEW CALCAREOUS NANNOFOSSIL TAXA FROM THE LOWER CRETACEOUS OF THE NORTH SEA
Martin Jakubowski,
North Wales, U.K.

Robertson Research International Ltd.,

Llandudno,Gwynedd

During the investigation of several well sections from the Moray Firth Basin of
the North Sea a number of new species were discovered. A new genus, five newspecies and four new combinations are described. The samples were examined fromreleased well sections under light and scanning electron microscopes.
Allholotypes and paratypes are light and electron microscope negatives and aredeposited at Robertson Research (Llandudno), except for the holotype ofEprolithus varolii which is deposited at British Petroleum's ResearchLaboratory.
GENUS: Crucibiscutum gen. nov.
Type species: Cruciplacolithus salebrosus BLACK (1971)
Diagnosis: Small elliptical coccoliths consisting of two shields made up ofimbricating elements.
The central area is spanned by a cross which isorientated along the principal axes of the ellipse. The distal shield, which isslightly larger, is connected to the proximal shield via a central tube.
Remarks:Thisnewgenus

hasbeenerectedtoaccommodatethespecies

Cruciplacolithus salebrosus BLACK (1971) and Cruciplacolithus hayi BLACK (1973)

which cannot easily be placed into any existing genera.
The Tertiary genus
Cruciplacolithus HAY and MOHLER (1967) has two cycles in the proximal shield
whereas Crucibiscutum has only one. Crucibiscutum differs from Biscutum BbACK(1959) by having an axial cross in the central area instead of an imperforate
central area filled with granules. It can be separated from Palaeopontosphaera
NOEL (1965), which possesses only a transverse bar in the central area, throughwhich passes an axial canal. Finally, it differs from Sollasites BLACK (1967)
which has a crossbar in the short axis but also has several crossbars parallelor subparallel to the long axis of the ellipse. The following new combinations
are introduced.

Crucibiscutum salebrosum_ (BLACK, 1971) JAKUBOWSKI, nov. comb. plate 1, figs.
16-17.

1971 Cruciplacolithus salebrosus BLACK, 1971, p. 379; plate 30, fig. 4.

Crucibiscutum hayi (BLACK, 1973) JAKUBOWSKI, nov. comb.
1973 Cruciplacolithus hayi BLACK, 1973 p. 66; plate 23, figs. 9-10.
GENUS: Eprolithus STOVER (1966).

Eprolithus varolii JAKUBOWSKI nov. sp., plate 1, figs. 1, 10-11.
Diagnosis: A species of Eprolithus with a thin wall composed of 16-20 segments
and a broad central diaphragm.
The segments of the wall are twisted andseparated into two halves by the disc shaped diaphragm, which consists of 16-20
thin, wedge shaped, non-imbricating elements. These elements do not meet at thecentre due to the presence of a small circular aperture.
Remarks: This species differs from Lithastrinus septentrionalis STRADNER (1963)
INA Newsletter vol.B- !986

by the presence of a wide diaphragm, two layers of twisted wall segments and, incross-section, by the H-shaped outline.
It differs from Eprolithus antiquus
PERCH-NIELSEN (1979) which has 10 wall segments and from Eprolithus apertior
BLACK (1973) and EproZithus fZoraZis (STRADNER, 1962) STOVER (1966) which have
only 9 wall segments.
Holotype: Neg. no. B.P./Pal. 2891; plate 1, fig. 1.
Paratype: Neg. no. MJ/06/85/14-15; plate 1, figs. 10-11.
Type locality: Otto Gott, near Hamburg, West Germany.
Type level: nutfieZdensis ammonite Zone, upper Aptian.
Range: Upper Barremian to Aptian.
GENUS: Gartnerago BUKRY (1969).

Gartnerago praeobZiquum JAKUBOWSKI nov. sp., plate 1, figs. 2-3, 12-13.
Diagnosis: A species of Gartnerago in which the central area is divided into 4
quadrants by an axial cross. Each of the 4 bars making up the axial crossterminates at the margin of the central area in a flaring 'arrowhead' and isdivided into 2 halves by a central suture.
Under the light microscope thespecies has a characteristic bright, outer cycle visible under both phase
contrast and cross-polarized light, as is typical of the genus Gartnerago.
Remarks:Thisspecies

isdistinguishedfromothermembersofthegenus

Gartnerago by possessing flaring, 'arrowhead' terminations to the axial crossand a central area with four open quadrants.

Holotype: Neg. no. MJ/N2/18-19; plate 1, figs. 2-3
Paratype: Neg. no. MJ/06/85/8-9; plate 1, figs. 12-13.
Type locality: Moray Firth Basin, North Sea.
Type level: Gartnerago praeobZiquum Zone, upper Albian.
Range: Lower - upper Albian.

Gartnerago theta (BLACK, 1959) JAKUBOWSKI nov. comb., plate 1, figs. 14-15.
1959 Discolithus theta BLACK in BLACK AND BARNES,fig. 1.

1959,p.

327;

plate12,Remarks: This species possesses a characteristic Gartnerago shield structure
including the bright outer cycle of elements visible under the light microscope.
The central area is divided into 2 halves by a single transverse bar. In wellpreserved specimens the central area either side of the transverse bar displays
perforations and a suture parallel to the long axis.
Range: Albian to Cenomanian.

INA Newsletter vol.S- 1986

39

GENUS: Lithraphidites DEFLANDRE (1963).

Lithraphidites moray-firthensis JAKUBOWSKI nov. sp., plate 1, figs. 4-5, 8-9.
Diagnosis: A species of Lithraphidites which is characterised by four keels
which are truncated at both ends and taper inwards toward a central tooth whichappears bright under cross-polarized light.
Remarks: The distinctive tapering of each keel towards a single central tooth
distinguishes Lithraphidites moray-firthensis from other keeled species ofLithraphidites, such as Lithraphidites grossopectinatus BUKRY (1969) which has arow of four teeth and from Lithraphidites quadratus BRAMLETTE AND MARTINI (1964)
and Lithraphidites praequadratus ROTH (1978) which do not possess any teeth.
Holotype: Neg. no. MJ/S2/21; plate 1, fig. 8.
Paratypes: Neg. no. MJ/S2/15; plate 1, fig. 9.
Neg. no. MJ/06/85/24-25; plate 1, figs. 4-5.
Type locality: Moray Firth Basin, North Sea.
Type level: Lithraphidites moray-firthensis Zone, lower Aptian.
Range: Upper Barremian to lower Aptian.
GENUS: Micrantholithus DEFLANDRE (1954)

Micrantholithus brevis JAKUBOWSKI nov. sp., plate 1, figs. 6-7.
Diagnosis: A species of MicranthoUthus where the free side of each segment
tapers inwards, very slightly, to form one positive angle and two shallow
negative angles.
Remarks: Micrantholithus brevis differs from the closely related Micrantholithus
speetonensis PERCH-NIELSEN (1979) by possessing much shallower negative angles

and a much lower positive angle. It also does not possess the very wide blackbands that run parallel to the sutures separating the segments, which arevisibleinMicrantholithus
speetonensis
undercross-polarized
light.
Micrantholithus brevis provides an obvious evolutionary link between
MicranthoUthus speetonensis and MicranthoUthus obtusus STRADNER (1963) (seeplate 1, fig. 27).
Holotype: Neg. no. MJ/08/85/35-36; plate 1, figs. 6-7.
Type locality: Moray Firth Basin, North Sea.
Type level: Micrantholithus speetonensis Zone, lower Valanginian.
Range: Lower Valanginian.

40

INA Newsletter vol.B- 1986

GENUS: PhanuZithus WIND AND WISE (1977).

Phanulithus anfractus JAKUBOWSKI nov. sp., plate 1, figs. 20-23.
Diagnosis: An elliptical coccolith constructed of four segments in different
crystallographic orientation exhibiting a moderately high birefringence. Ashort, shallow, S-shaped suture separates the 2 segments which lie about theshort axis. The two remaining segments, which are positioned at the ends of theellipse, are separated from those on the short axis by deeply incised, zigzag
sutures.
Remarks: Phanulithus anfractus differs from all previously described species ofPhanuZithus by possessing curved and zigzag sutures.
Holotype: Neg. no. MJ/04/85/30-31; plate 1, figs. 20-21.
Paratype: Neg. no. MJ/01/85/11-12; plate 1, figs. 22-23.
Type locality: Moray Firth Basin, North Sea.
Type level: PhanuZithus anfractus Zone, upper Albian to lower Cenomanian.
Range: Upper Albian to lower Cenomanian.
GENUS: Conusphaera TREJO (1969).

Conusphaera rothii (THIERSTEIN, 1971) JAKUBOWSKI nov. comb., plate 1, figs.
24-26.

1971 CretaturbeZZa rothii THIERSTEIN, 1971, p. 483; plate 3, figs. 1-5.
Remarks:

Thisspecies

hasoften been placedin synonymy with Conusphaera
However, it differs markedly inpossessing a shorter cone, consisting of inclined twisted plates which, in thelight microscope, produce a characteristic cross-hatching along the long axis.
Conusphaera mexicana has a much longer cone which does not possess any twistedplates; they are straight and parallel to the sides of the cone.

mexicana TREJO (1969) (plate 1, figs. 28-29).

ACKNOWLEDGEMENTS
I would like to thank the directors and management of Robertson ResearchInternational Ltd. for their support and financial assistance.
I am also
greatly indebted to Dr Jason Crux (B.P. Research Centre) for providing scanningelectron micrographs of EproZithus varolii and to Dr Osman Varol and Dr MagdyGirgis (Robertson Research) for their valuable and much appreciated help andadvice.
REFERENCESBLACK, M., 1967.
New names for some coccolith taxa.
Proc. geol. Soc.,
no. 1640, 139-45.
BLACK, M., 1971. Coccoliths of the Speeton Clay and Sutterby Marl.
Proc.
Yorkshire geol. Soc., 38(3), 381-424.
BLACK, M., 1972, 1973, 1975. British Lower Cretaceous coccoliths. I. GaultClay.
1,2,3. Monogr. paZaeontogr. Soc. London. 126, 1~48; 127, 49-112;
129' 113-42.

INA Newsletter vol.8 - 1986
41

BLACK, M. and BARNES, 1959. The structure of coccoliths from the English Chalk.
Geol. Mag., 96, 321-8.
BRAMLETTE, M.N. and MARTINI, E., 1964.
The great change in calcareous
nannoplankton
fossils
betweenMaestrichtianandDanian.
theMicropalaeontology, 10, 291-322.
BUKRY, D., 1969. Upper Cretaceous coccoliths from Texas and Europe. Univ.
Kansas Paleontol. Contrib., 51 (Protista 2), 1-79.
DEFLANDRE, G., 1959.
Sur les nannofossiles calcaires et leur systematique.
Rev. Micropaleontol., 2, 127-52.
DEFLANDRE,G. ,1963.
Sur le s Microrhabdulides,
famillenouvelledenannofossiles calcaires. C.r. Seances Acad. Sci. Paris, 256, 3484-6.
DEFLANDRE, G. and FERT, C., 1954.
Observations sur les Cocclithophorides
actuels et fossiles en microscopie ordinaire et electronique. Ann.
Paleontol., 40, 115-76.
HAY, W.W. and MOHLER, H.P., 1967. Calcareous nannoplankton from early Tertiary
rocks at Pont Labau, France, and Paleocene - Eocene correlations. J.
Paleontol., 41, 1505-41.
JAKUBOWSKI, M: (in press). A proposed Lower Cretaceous nannofossil zonation
scheme for the Moray Firth area of the North Sea. Jb. Geol. B.-A.
NOEL, D., 1965. Sur les Coccolithes de Jurassique Europeen et d'Afrique de Nord.
Edition du CNRS Paris, 209 pp.
PERCH-NIELSEN, K., 1979. . Calcareous nannofossils from the Cretaceous between
the North Sea and the Mediterranean. IUGS Series A, 6, 223-72.
ROTH, P.H., 1978. Cretaceous nannoplankton biostratigraphy and oceanography of
the Northwestern Atlantic Ocean. Initial. Rep. Deep Sea drill. Proj., 44,731-59.
SISSINGH, W., 1977.
Biostratigraphy of Cretaceous calcareous nannoplankton.
Geol. Mijnbouw., 56(1), 37-65.
STOVER, L.E., 1966.
Cretaceous coccoliths and associated nannofossils from
France and the Netherlands. Micropaleontology, 12, 133-67.
STRADNER, H., 1962. Uber neue und wenig bekannte Nannofossilien aus Kreide undAlttertiHr. Verh. geol. Bundesanst. (Wien), 1962, 363-77.
STRADNER, H., 1963. New contributions to Mesozoic stratigraphy by means ofnannofossils. Proceedings of the 6th World Petrol. congr. Sect. 1, paper 4(preprint), 1-16.
THIERSTEIN, H.R., 1971.
Tentative Lower Cretaceous nannoplankton zonation.
Eclog. geol. Helv., 64, 459-88.
TREJO, M., 1969. Conusphaera mexicana, un nuevo coccolitoforido del Jurassico
Superior de Mexico. Revista Inst. Mexicano Petrol., 1(4), 5-15.
WISE, S.W. Jr. and WIND, F.H., 1977.
Mesozoic and Cenozoic calcareous
nannofossils recovered by DSDP Leg 36 drilling on the Falkland Plateau, SW
Atlantic sector of the Southern Ocean. Initial Rep. Deep Sea drill. Proj.,
36, 296-309.

INA Newsletter vol.B- 198642

SAN MIGUEL, M.(1977).- Contribuci6n al estudio de los Discoasteridos. Bol.R.
Soc.Esp.Hi~t.Nat. 75(1-4)~ 115-165
STRADNER, H.(1973).- Catalogue of Calcareous Nannoplankton from sediments ofNe?gene age in the Eastern North Atlantic and Mediterranean Sea.
In. W.B.F. RYAN, K.J. HSU, et al. Init. Rep. DSDP, 13(II), 11371199
THEODORIDIS, S.A.(1983).- On the legitimacy of the generic name Discoaster
TAN, 1927 ex TAN, 1931. INA newsl. 5(1), 15-21(1984).- Calcareous nannofossil biozonation of the Mioceneand revision of the Helicoliths and Discoasters. Utrecht Micropal. Bull. 32, 1-271+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++UFO 3: A nannofossil found in the middle Eocene from the Aquitaine Basin,S.W. France.
by Catherine Mancion
6, S~uare Lton Blum, 92800 Puteaux, France.
Tiny nannofossil, possibly barrel-shaped, with a circular, 5.3u widebasal disc consisting of 24 elements arranged in a subradial manner .. The
disc is gently depressed aver 2/3 of its area. The structure a' its center
is unclear due to preservation. The side view was not observed but thelateral wall appears to be formed of overlapping plates.
Location: Found in middle Eocene blue marls exposed in the Miretrain
Quarry <Aquitaine basin). The nannofossil assemblage found in these marls
includes Chiasmolithus gigas, Discoaster martinii, Nannotetrina cristata,H. fulgens and Rhabdosphaera gladius and is diagnostic of Zone NP 15.
The planctonic foraminifera indicate the Globigerinatheka subconglobata
subconglobata Zone of Belli <1957, 19661.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

PLATE 1
M. Jakubowski: New calcareous nannofossil taxa from the Lower Cretaceous of
the North Sea.
Figs. 1, 10-11: Eprolithus varolii JAKUBOWSKI nov. sp.
Fig. 1:
Holotype, B.P./Pal 2891; side view, x 10000; Sample OG 57 1
Otto Gott.
Figs. 10-11: Paratype, MJ/06/85/14-15; Fig.10, phase contrast. Fig.11,
cross-polarized light, x 2400; Sample Sun Oil 20/7-A1,6720',
Figs. 2-3, 12-13: Gartnerago praeobliquum JAKUBOWSKI nov. sp.
Figs. 2-3:
Holotype, MJ/N2/18-19; Fig.2, phase contrast, Fig.3, crosspolarized light, x 2400; Sample Occidental 13/28-1, 4780',
Figs. 12-13: Paratype, MJ/06/85/8-9; Fig.12, phase contrast, Fig. 13,
cross-polarized light, x 2400; Sample Sun Oil 20/7-Al,7040'.

INA Newsletter vol.B- 198635

PLATE I

<PLATE 1, cent. lFigs. 4-5, 8-9: Lithraphidites moray-firthensis JAKUBOWSKI nov. sp.
Fig. 8:
Holotype, MJ/S2/21; side view, x 5800; Sample B.P. 14/4-1,1320m.
Fig. 9:Paratype, MJ/82?15; side view, x 5800; Sample B.P. 14/4-1 11320m.
Figs. 4-5:
Paratype, MJ/06/85/24-25; Fig.4, phase contrast, Fig.S,
cross-polarized light, x 2400; Sample B.P. 14/4-1, 1320m.
Figs. 6-7: Hicrantholithus brevis JAKUBOWSKI nov. sp.
Holotype, MJ/08/85/35-36, Sample B.P. 14/4-1, 1685.5m 1 x2400; Fig.6, phase contrast, Fig.7, cross-polarized light.
Figs. 14-15: Ga.rtnerago theta <BLACK, 1959) JAKUBOWSKI nov. comb.
Sample Sun Oil 20/7-Al, 5990' 1 x 2400; Fig.14 1contrast, Fig.l5, cross-polarized light.

phaseFigs. 16-17: Crucibiscutum salebrosum <BLACK, 1971l JAKUBOWSKI nov. comb.
Sample S-19 1 x 2400; Fig.16, phse contrast, Fig.17, crosspolarized light.
Figs. 18-19: Hicrantholithus speetonensis PERCH-NIELSEN 1979; Sample B.P.
14/4-1 1 1660m 1 x 2400; Fig.18 1 phase contrast, Fig.l5,cross-polarized light.
Figs. 20-23: Phanulithus anfractus JAKUBOWSKI nov. sp.
Figs. 20-21: Holotype, MJ/04/85/30-31; Fig.20, phase contrast, Fig.21,cross-polarized light, x 2400; Sample Texaco 15/16-5,11420'.
Figs. 22-23: Paratype, MJ/01/85/11-12; Fig.22 1 phase contrast, Fig.23,cross-polarized light, x 2400; Sample Sun Oil 2017-At,6200'.
Figs. 24-26: Conusphaera rothii (TH!ERSTEIN, 1971l JAKUBOWSKI nov. comb.
Sample Sun Oil 20/7-Al, 7400', x 2400; Fig.24, phasecontrast, Figs.25-26 1 cross-polarized light.
Fig. 27: Hicrantholithus obtusus STRADNER, 1963; Sample Nettleton AF-1,
2400 1 phase contrast.

l~Figs. 28-29: Conusphaera aexicana TREJO,
well, x 2400; Fig.28,
polarized light.

phase1969;

Sample East Madagascar
contrast, Fig.29
cross-C. Manc:ion: UFO 3: A nannofossil
Aquitaine Basin, S.W. France.

inmiddle

found

theEocenefrom

theFig. 30: UFO 3 1 4500 x.

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